We agreed on using ```&&``` and ```||``` instead of ```and``` and ```or```, because of their strange priority. The case is similar with ```not``` and ```!```. So if we use ```not``` in methods like this we are inconsistent with the other part of the code.

On the other hand using it in methods like this makes them a bit easier to read. And we'll be consistent in the context of these methods.

So it's 50:50.